drivers/iio/health/afe4403.c

   1 /*
   2  * AFE4403 Heart Rate Monitors and Low-Cost Pulse Oximeters
   3  *
   4  * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
   5  *      Andrew F. Davis <afd@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  */
  16
  17 #include <linux/device.h>
  18 #include <linux/err.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/regmap.h>
  23 #include <linux/spi/spi.h>
  24 #include <linux/sysfs.h>
  25 #include <linux/regulator/consumer.h>
  26
  27 #include <linux/iio/iio.h>
  28 #include <linux/iio/sysfs.h>
  29 #include <linux/iio/buffer.h>
  30 #include <linux/iio/trigger.h>
  31 #include <linux/iio/triggered_buffer.h>
  32 #include <linux/iio/trigger_consumer.h>
  33
  34 #include "afe440x.h"
  35
  36 #define AFE4403_DRIVER_NAME             "afe4403"
  37
  38 /* AFE4403 Registers */
  39 #define AFE4403_TIAGAIN                 0x20
  40 #define AFE4403_TIA_AMB_GAIN            0x21
  41
  42 enum afe4403_fields {
  43         /* Gains */
  44         F_RF_LED1, F_CF_LED1,
  45         F_RF_LED, F_CF_LED,
  46
  47         /* LED Current */
  48         F_ILED1, F_ILED2,
  49
  50         /* sentinel */
  51         F_MAX_FIELDS
  52 };
  53
  54 static const struct reg_field afe4403_reg_fields[] = {
  55         /* Gains */
  56         [F_RF_LED1]     = REG_FIELD(AFE4403_TIAGAIN, 0, 2),
  57         [F_CF_LED1]     = REG_FIELD(AFE4403_TIAGAIN, 3, 7),
  58         [F_RF_LED]      = REG_FIELD(AFE4403_TIA_AMB_GAIN, 0, 2),
  59         [F_CF_LED]      = REG_FIELD(AFE4403_TIA_AMB_GAIN, 3, 7),
  60         /* LED Current */
  61         [F_ILED1]       = REG_FIELD(AFE440X_LEDCNTRL, 0, 7),
  62         [F_ILED2]       = REG_FIELD(AFE440X_LEDCNTRL, 8, 15),
  63 };
  64
  65 /**
  66  * struct afe4403_data - AFE4403 device instance data
  67  * @dev: Device structure
  68  * @spi: SPI device handle
  69  * @regmap: Register map of the device
  70  * @fields: Register fields of the device
  71  * @regulator: Pointer to the regulator for the IC
  72  * @trig: IIO trigger for this device
  73  * @irq: ADC_RDY line interrupt number
  74  */
  75 struct afe4403_data {
  76         struct device *dev;
  77         struct spi_device *spi;
  78         struct regmap *regmap;
  79         struct regmap_field *fields[F_MAX_FIELDS];
  80         struct regulator *regulator;
  81         struct iio_trigger *trig;
  82         int irq;
  83 };
  84
  85 enum afe4403_chan_id {
  86         LED2 = 1,
  87         ALED2,
  88         LED1,
  89         ALED1,
  90         LED2_ALED2,
  91         LED1_ALED1,
  92 };
  93
  94 static const unsigned int afe4403_channel_values[] = {
  95         [LED2] = AFE440X_LED2VAL,
  96         [ALED2] = AFE440X_ALED2VAL,
  97         [LED1] = AFE440X_LED1VAL,
  98         [ALED1] = AFE440X_ALED1VAL,
  99         [LED2_ALED2] = AFE440X_LED2_ALED2VAL,
 100         [LED1_ALED1] = AFE440X_LED1_ALED1VAL,
 101 };
 102
 103 static const unsigned int afe4403_channel_leds[] = {
 104         [LED2] = F_ILED2,
 105         [LED1] = F_ILED1,
 106 };
 107
 108 static const struct iio_chan_spec afe4403_channels[] = {
 109         /* ADC values */
 110         AFE440X_INTENSITY_CHAN(LED2, 0),
 111         AFE440X_INTENSITY_CHAN(ALED2, 0),
 112         AFE440X_INTENSITY_CHAN(LED1, 0),
 113         AFE440X_INTENSITY_CHAN(ALED1, 0),
 114         AFE440X_INTENSITY_CHAN(LED2_ALED2, 0),
 115         AFE440X_INTENSITY_CHAN(LED1_ALED1, 0),
 116         /* LED current */
 117         AFE440X_CURRENT_CHAN(LED2),
 118         AFE440X_CURRENT_CHAN(LED1),
 119 };
 120
 121 static const struct afe440x_val_table afe4403_res_table[] = {
 122         { 500000 }, { 250000 }, { 100000 }, { 50000 },
 123         { 25000 }, { 10000 }, { 1000000 }, { 0 },
 124 };
 125 AFE440X_TABLE_ATTR(in_intensity_resistance_available, afe4403_res_table);
 126
 127 static const struct afe440x_val_table afe4403_cap_table[] = {
 128         { 0, 5000 }, { 0, 10000 }, { 0, 20000 }, { 0, 25000 },
 129         { 0, 30000 }, { 0, 35000 }, { 0, 45000 }, { 0, 50000 },
 130         { 0, 55000 }, { 0, 60000 }, { 0, 70000 }, { 0, 75000 },
 131         { 0, 80000 }, { 0, 85000 }, { 0, 95000 }, { 0, 100000 },
 132         { 0, 155000 }, { 0, 160000 }, { 0, 170000 }, { 0, 175000 },
 133         { 0, 180000 }, { 0, 185000 }, { 0, 195000 }, { 0, 200000 },
 134         { 0, 205000 }, { 0, 210000 }, { 0, 220000 }, { 0, 225000 },
 135         { 0, 230000 }, { 0, 235000 }, { 0, 245000 }, { 0, 250000 },
 136 };
 137 AFE440X_TABLE_ATTR(in_intensity_capacitance_available, afe4403_cap_table);
 138
 139 static ssize_t afe440x_show_register(struct device *dev,
 140                                      struct device_attribute *attr,
 141                                      char *buf)
 142 {
 143         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 144         struct afe4403_data *afe = iio_priv(indio_dev);
 145         struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
 146         unsigned int reg_val;
 147         int vals[2];
 148         int ret;
 149
 150         ret = regmap_field_read(afe->fields[afe440x_attr->field], &reg_val);
 151         if (ret)
 152                 return ret;
 153
 154         if (reg_val >= afe440x_attr->table_size)
 155                 return -EINVAL;
 156
 157         vals[0] = afe440x_attr->val_table[reg_val].integer;
 158         vals[1] = afe440x_attr->val_table[reg_val].fract;
 159
 160         return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
 161 }
 162
 163 static ssize_t afe440x_store_register(struct device *dev,
 164                                       struct device_attribute *attr,
 165                                       const char *buf, size_t count)
 166 {
 167         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 168         struct afe4403_data *afe = iio_priv(indio_dev);
 169         struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
 170         int val, integer, fract, ret;
 171
 172         ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
 173         if (ret)
 174                 return ret;
 175
 176         for (val = 0; val < afe440x_attr->table_size; val++)
 177                 if (afe440x_attr->val_table[val].integer == integer &&
 178                     afe440x_attr->val_table[val].fract == fract)
 179                         break;
 180         if (val == afe440x_attr->table_size)
 181                 return -EINVAL;
 182
 183         ret = regmap_field_write(afe->fields[afe440x_attr->field], val);
 184         if (ret)
 185                 return ret;
 186
 187         return count;
 188 }
 189
 190 static AFE440X_ATTR(in_intensity1_resistance, F_RF_LED, afe4403_res_table);
 191 static AFE440X_ATTR(in_intensity1_capacitance, F_CF_LED, afe4403_cap_table);
 192
 193 static AFE440X_ATTR(in_intensity2_resistance, F_RF_LED, afe4403_res_table);
 194 static AFE440X_ATTR(in_intensity2_capacitance, F_CF_LED, afe4403_cap_table);
 195
 196 static AFE440X_ATTR(in_intensity3_resistance, F_RF_LED1, afe4403_res_table);
 197 static AFE440X_ATTR(in_intensity3_capacitance, F_CF_LED1, afe4403_cap_table);
 198
 199 static AFE440X_ATTR(in_intensity4_resistance, F_RF_LED1, afe4403_res_table);
 200 static AFE440X_ATTR(in_intensity4_capacitance, F_CF_LED1, afe4403_cap_table);
 201
 202 static struct attribute *afe440x_attributes[] = {
 203         &dev_attr_in_intensity_resistance_available.attr,
 204         &dev_attr_in_intensity_capacitance_available.attr,
 205         &afe440x_attr_in_intensity1_resistance.dev_attr.attr,
 206         &afe440x_attr_in_intensity1_capacitance.dev_attr.attr,
 207         &afe440x_attr_in_intensity2_resistance.dev_attr.attr,
 208         &afe440x_attr_in_intensity2_capacitance.dev_attr.attr,
 209         &afe440x_attr_in_intensity3_resistance.dev_attr.attr,
 210         &afe440x_attr_in_intensity3_capacitance.dev_attr.attr,
 211         &afe440x_attr_in_intensity4_resistance.dev_attr.attr,
 212         &afe440x_attr_in_intensity4_capacitance.dev_attr.attr,
 213         NULL
 214 };
 215
 216 static const struct attribute_group afe440x_attribute_group = {
 217         .attrs = afe440x_attributes
 218 };
 219
 220 static int afe4403_read(struct afe4403_data *afe, unsigned int reg, u32 *val)
 221 {
 222         u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
 223         u8 rx[3];
 224         int ret;
 225
 226         /* Enable reading from the device */
 227         ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
 228         if (ret)
 229                 return ret;
 230
 231         ret = spi_write_then_read(afe->spi, &reg, 1, rx, 3);
 232         if (ret)
 233                 return ret;
 234
 235         *val = (rx[0] << 16) |
 236                 (rx[1] << 8) |
 237                 (rx[2]);
 238
 239         /* Disable reading from the device */
 240         tx[3] = AFE440X_CONTROL0_WRITE;
 241         ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
 242         if (ret)
 243                 return ret;
 244
 245         return 0;
 246 }
 247
 248 static int afe4403_read_raw(struct iio_dev *indio_dev,
 249                             struct iio_chan_spec const *chan,
 250                             int *val, int *val2, long mask)
 251 {
 252         struct afe4403_data *afe = iio_priv(indio_dev);
 253         unsigned int reg = afe4403_channel_values[chan->address];
 254         unsigned int field = afe4403_channel_leds[chan->address];
 255         int ret;
 256
 257         switch (chan->type) {
 258         case IIO_INTENSITY:
 259                 switch (mask) {
 260                 case IIO_CHAN_INFO_RAW:
 261                         ret = afe4403_read(afe, reg, val);
 262                         if (ret)
 263                                 return ret;
 264                         return IIO_VAL_INT;
 265                 }
 266                 break;
 267         case IIO_CURRENT:
 268                 switch (mask) {
 269                 case IIO_CHAN_INFO_RAW:
 270                         ret = regmap_field_read(afe->fields[field], val);
 271                         if (ret)
 272                                 return ret;
 273                         return IIO_VAL_INT;
 274                 case IIO_CHAN_INFO_SCALE:
 275                         *val = 0;
 276                         *val2 = 800000;
 277                         return IIO_VAL_INT_PLUS_MICRO;
 278                 }
 279                 break;
 280         default:
 281                 break;
 282         }
 283
 284         return -EINVAL;
 285 }
 286
 287 static int afe4403_write_raw(struct iio_dev *indio_dev,
 288                              struct iio_chan_spec const *chan,
 289                              int val, int val2, long mask)
 290 {
 291         struct afe4403_data *afe = iio_priv(indio_dev);
 292         unsigned int field = afe4403_channel_leds[chan->address];
 293
 294         switch (chan->type) {
 295         case IIO_CURRENT:
 296                 switch (mask) {
 297                 case IIO_CHAN_INFO_RAW:
 298                         return regmap_field_write(afe->fields[field], val);
 299                 }
 300                 break;
 301         default:
 302                 break;
 303         }
 304
 305         return -EINVAL;
 306 }
 307
 308 static const struct iio_info afe4403_iio_info = {
 309         .attrs = &afe440x_attribute_group,
 310         .read_raw = afe4403_read_raw,
 311         .write_raw = afe4403_write_raw,
 312         .driver_module = THIS_MODULE,
 313 };
 314
 315 static irqreturn_t afe4403_trigger_handler(int irq, void *private)
 316 {
 317         struct iio_poll_func *pf = private;
 318         struct iio_dev *indio_dev = pf->indio_dev;
 319         struct afe4403_data *afe = iio_priv(indio_dev);
 320         int ret, bit, i = 0;
 321         s32 buffer[8];
 322         u8 tx[4] = {AFE440X_CONTROL0, 0x0, 0x0, AFE440X_CONTROL0_READ};
 323         u8 rx[3];
 324
 325         /* Enable reading from the device */
 326         ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
 327         if (ret)
 328                 goto err;
 329
 330         for_each_set_bit(bit, indio_dev->active_scan_mask,
 331                          indio_dev->masklength) {
 332                 ret = spi_write_then_read(afe->spi,
 333                                           &afe4403_channel_values[bit], 1,
 334                                           rx, 3);
 335                 if (ret)
 336                         goto err;
 337
 338                 buffer[i++] = (rx[0] << 16) |
 339                                 (rx[1] << 8) |
 340                                 (rx[2]);
 341         }
 342
 343         /* Disable reading from the device */
 344         tx[3] = AFE440X_CONTROL0_WRITE;
 345         ret = spi_write_then_read(afe->spi, tx, 4, NULL, 0);
 346         if (ret)
 347                 goto err;
 348
 349         iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
 350 err:
 351         iio_trigger_notify_done(indio_dev->trig);
 352
 353         return IRQ_HANDLED;
 354 }
 355
 356 static const struct iio_trigger_ops afe4403_trigger_ops = {
 357         .owner = THIS_MODULE,
 358 };
 359
 360 #define AFE4403_TIMING_PAIRS                    \
 361         { AFE440X_LED2STC,      0x000050 },     \
 362         { AFE440X_LED2ENDC,     0x0003e7 },     \
 363         { AFE440X_LED1LEDSTC,   0x0007d0 },     \
 364         { AFE440X_LED1LEDENDC,  0x000bb7 },     \
 365         { AFE440X_ALED2STC,     0x000438 },     \
 366         { AFE440X_ALED2ENDC,    0x0007cf },     \
 367         { AFE440X_LED1STC,      0x000820 },     \
 368         { AFE440X_LED1ENDC,     0x000bb7 },     \
 369         { AFE440X_LED2LEDSTC,   0x000000 },     \
 370         { AFE440X_LED2LEDENDC,  0x0003e7 },     \
 371         { AFE440X_ALED1STC,     0x000c08 },     \
 372         { AFE440X_ALED1ENDC,    0x000f9f },     \
 373         { AFE440X_LED2CONVST,   0x0003ef },     \
 374         { AFE440X_LED2CONVEND,  0x0007cf },     \
 375         { AFE440X_ALED2CONVST,  0x0007d7 },     \
 376         { AFE440X_ALED2CONVEND, 0x000bb7 },     \
 377         { AFE440X_LED1CONVST,   0x000bbf },     \
 378         { AFE440X_LED1CONVEND,  0x009c3f },     \
 379         { AFE440X_ALED1CONVST,  0x000fa7 },     \
 380         { AFE440X_ALED1CONVEND, 0x001387 },     \
 381         { AFE440X_ADCRSTSTCT0,  0x0003e8 },     \
 382         { AFE440X_ADCRSTENDCT0, 0x0003eb },     \
 383         { AFE440X_ADCRSTSTCT1,  0x0007d0 },     \
 384         { AFE440X_ADCRSTENDCT1, 0x0007d3 },     \
 385         { AFE440X_ADCRSTSTCT2,  0x000bb8 },     \
 386         { AFE440X_ADCRSTENDCT2, 0x000bbb },     \
 387         { AFE440X_ADCRSTSTCT3,  0x000fa0 },     \
 388         { AFE440X_ADCRSTENDCT3, 0x000fa3 },     \
 389         { AFE440X_PRPCOUNT,     0x009c3f },     \
 390         { AFE440X_PDNCYCLESTC,  0x001518 },     \
 391         { AFE440X_PDNCYCLEENDC, 0x00991f }
 392
 393 static const struct reg_sequence afe4403_reg_sequences[] = {
 394         AFE4403_TIMING_PAIRS,
 395         { AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
 396         { AFE4403_TIAGAIN, AFE440X_TIAGAIN_ENSEPGAIN },
 397 };
 398
 399 static const struct regmap_range afe4403_yes_ranges[] = {
 400         regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
 401 };
 402
 403 static const struct regmap_access_table afe4403_volatile_table = {
 404         .yes_ranges = afe4403_yes_ranges,
 405         .n_yes_ranges = ARRAY_SIZE(afe4403_yes_ranges),
 406 };
 407
 408 static const struct regmap_config afe4403_regmap_config = {
 409         .reg_bits = 8,
 410         .val_bits = 24,
 411
 412         .max_register = AFE440X_PDNCYCLEENDC,
 413         .cache_type = REGCACHE_RBTREE,
 414         .volatile_table = &afe4403_volatile_table,
 415 };
 416
 417 static const struct of_device_id afe4403_of_match[] = {
 418         { .compatible = "ti,afe4403", },
 419         { /* sentinel */ }
 420 };
 421 MODULE_DEVICE_TABLE(of, afe4403_of_match);
 422
 423 static int __maybe_unused afe4403_suspend(struct device *dev)
 424 {
 425         struct iio_dev *indio_dev = spi_get_drvdata(to_spi_device(dev));
 426         struct afe4403_data *afe = iio_priv(indio_dev);
 427         int ret;
 428
 429         ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
 430                                  AFE440X_CONTROL2_PDN_AFE,
 431                                  AFE440X_CONTROL2_PDN_AFE);
 432         if (ret)
 433                 return ret;
 434
 435         ret = regulator_disable(afe->regulator);
 436         if (ret) {
 437                 dev_err(dev, "Unable to disable regulator\n");
 438                 return ret;
 439         }
 440
 441         return 0;
 442 }
 443
 444 static int __maybe_unused afe4403_resume(struct device *dev)
 445 {
 446         struct iio_dev *indio_dev = spi_get_drvdata(to_spi_device(dev));
 447         struct afe4403_data *afe = iio_priv(indio_dev);
 448         int ret;
 449
 450         ret = regulator_enable(afe->regulator);
 451         if (ret) {
 452                 dev_err(dev, "Unable to enable regulator\n");
 453                 return ret;
 454         }
 455
 456         ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
 457                                  AFE440X_CONTROL2_PDN_AFE, 0);
 458         if (ret)
 459                 return ret;
 460
 461         return 0;
 462 }
 463
 464 static SIMPLE_DEV_PM_OPS(afe4403_pm_ops, afe4403_suspend, afe4403_resume);
 465
 466 static int afe4403_probe(struct spi_device *spi)
 467 {
 468         struct iio_dev *indio_dev;
 469         struct afe4403_data *afe;
 470         int i, ret;
 471
 472         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*afe));
 473         if (!indio_dev)
 474                 return -ENOMEM;
 475
 476         afe = iio_priv(indio_dev);
 477         spi_set_drvdata(spi, indio_dev);
 478
 479         afe->dev = &spi->dev;
 480         afe->spi = spi;
 481         afe->irq = spi->irq;
 482
 483         afe->regmap = devm_regmap_init_spi(spi, &afe4403_regmap_config);
 484         if (IS_ERR(afe->regmap)) {
 485                 dev_err(afe->dev, "Unable to allocate register map\n");
 486                 return PTR_ERR(afe->regmap);
 487         }
 488
 489         for (i = 0; i < F_MAX_FIELDS; i++) {
 490                 afe->fields[i] = devm_regmap_field_alloc(afe->dev, afe->regmap,
 491                                                          afe4403_reg_fields[i]);
 492                 if (IS_ERR(afe->fields[i])) {
 493                         dev_err(afe->dev, "Unable to allocate regmap fields\n");
 494                         return PTR_ERR(afe->fields[i]);
 495                 }
 496         }
 497
 498         afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
 499         if (IS_ERR(afe->regulator)) {
 500                 dev_err(afe->dev, "Unable to get regulator\n");
 501                 return PTR_ERR(afe->regulator);
 502         }
 503         ret = regulator_enable(afe->regulator);
 504         if (ret) {
 505                 dev_err(afe->dev, "Unable to enable regulator\n");
 506                 return ret;
 507         }
 508
 509         ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
 510                            AFE440X_CONTROL0_SW_RESET);
 511         if (ret) {
 512                 dev_err(afe->dev, "Unable to reset device\n");
 513                 goto err_disable_reg;
 514         }
 515
 516         ret = regmap_multi_reg_write(afe->regmap, afe4403_reg_sequences,
 517                                      ARRAY_SIZE(afe4403_reg_sequences));
 518         if (ret) {
 519                 dev_err(afe->dev, "Unable to set register defaults\n");
 520                 goto err_disable_reg;
 521         }
 522
 523         indio_dev->modes = INDIO_DIRECT_MODE;
 524         indio_dev->dev.parent = afe->dev;
 525         indio_dev->channels = afe4403_channels;
 526         indio_dev->num_channels = ARRAY_SIZE(afe4403_channels);
 527         indio_dev->name = AFE4403_DRIVER_NAME;
 528         indio_dev->info = &afe4403_iio_info;
 529
 530         if (afe->irq > 0) {
 531                 afe->trig = devm_iio_trigger_alloc(afe->dev,
 532                                                    "%s-dev%d",
 533                                                    indio_dev->name,
 534                                                    indio_dev->id);
 535                 if (!afe->trig) {
 536                         dev_err(afe->dev, "Unable to allocate IIO trigger\n");
 537                         ret = -ENOMEM;
 538                         goto err_disable_reg;
 539                 }
 540
 541                 iio_trigger_set_drvdata(afe->trig, indio_dev);
 542
 543                 afe->trig->ops = &afe4403_trigger_ops;
 544                 afe->trig->dev.parent = afe->dev;
 545
 546                 ret = iio_trigger_register(afe->trig);
 547                 if (ret) {
 548                         dev_err(afe->dev, "Unable to register IIO trigger\n");
 549                         goto err_disable_reg;
 550                 }
 551
 552                 ret = devm_request_threaded_irq(afe->dev, afe->irq,
 553                                                 iio_trigger_generic_data_rdy_poll,
 554                                                 NULL, IRQF_ONESHOT,
 555                                                 AFE4403_DRIVER_NAME,
 556                                                 afe->trig);
 557                 if (ret) {
 558                         dev_err(afe->dev, "Unable to request IRQ\n");
 559                         goto err_trig;
 560                 }
 561         }
 562
 563         ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
 564                                          afe4403_trigger_handler, NULL);
 565         if (ret) {
 566                 dev_err(afe->dev, "Unable to setup buffer\n");
 567                 goto err_trig;
 568         }
 569
 570         ret = iio_device_register(indio_dev);
 571         if (ret) {
 572                 dev_err(afe->dev, "Unable to register IIO device\n");
 573                 goto err_buff;
 574         }
 575
 576         return 0;
 577
 578 err_buff:
 579         iio_triggered_buffer_cleanup(indio_dev);
 580 err_trig:
 581         if (afe->irq > 0)
 582                 iio_trigger_unregister(afe->trig);
 583 err_disable_reg:
 584         regulator_disable(afe->regulator);
 585
 586         return ret;
 587 }
 588
 589 static int afe4403_remove(struct spi_device *spi)
 590 {
 591         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 592         struct afe4403_data *afe = iio_priv(indio_dev);
 593         int ret;
 594
 595         iio_device_unregister(indio_dev);
 596
 597         iio_triggered_buffer_cleanup(indio_dev);
 598
 599         if (afe->irq > 0)
 600                 iio_trigger_unregister(afe->trig);
 601
 602         ret = regulator_disable(afe->regulator);
 603         if (ret) {
 604                 dev_err(afe->dev, "Unable to disable regulator\n");
 605                 return ret;
 606         }
 607
 608         return 0;
 609 }
 610
 611 static const struct spi_device_id afe4403_ids[] = {
 612         { "afe4403", 0 },
 613         { /* sentinel */ }
 614 };
 615 MODULE_DEVICE_TABLE(spi, afe4403_ids);
 616
 617 static struct spi_driver afe4403_spi_driver = {
 618         .driver = {
 619                 .name = AFE4403_DRIVER_NAME,
 620                 .of_match_table = afe4403_of_match,
 621                 .pm = &afe4403_pm_ops,
 622         },
 623         .probe = afe4403_probe,
 624         .remove = afe4403_remove,
 625         .id_table = afe4403_ids,
 626 };
 627 module_spi_driver(afe4403_spi_driver);
 628
 629 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
 630 MODULE_DESCRIPTION("TI AFE4403 Heart Rate Monitor and Pulse Oximeter AFE");
 631 MODULE_LICENSE("GPL v2");